One type of fence typically used in rural areas is a wire fence comprising a plurality of spaced apart, substantially parallel wires supported periodically along the fence line by fence posts. In addition to fence posts, or sometimes as an alternative, fence droppers (also known as fence stays or fence spacers) are used periodically to maintain the wires in a spaced relationship. Fence droppers are particularly useful in maintaining the spaced relationship between the wires after an impact on the fence, for example from a large animal, by transferring loads from one or two wires to the whole fence. Fence droppers also help maintain the integrity of the fence as the fence ages because the wires tend to sag over time if they are not re-tensioned. Wire fences are often electrified to keep animals away from the fence and to deter intruders to the fenced property.
Most known fence droppers are elongate and span the full vertical height of the fence occupied by the wires or a large proportion of the vertical height of the fence. Fence droppers may or may not be inserted into the ground and can be made from a range of materials, such as metals and plastics. A wide range of designs are known for fence droppers and for attaching the droppers to the wires. Each design typically possesses a number of advantages and disadvantages relating to one or more of ease and cost of production, amount of materials consumed, ease of packaging, transportation and/or installation, durability and/or ease of maintenance. It has proven difficult to maximise the advantages of such fence droppers whilst minimising the drawbacks.
One common design of fence dropper and means of attaching the wires thereto comprises a plastic fence dropper, optionally having a plurality of protrusions or slots for accommodating the wires, and a metal clip which secures the wires in place against the dropper. There are a large number of variations of this arrangement, but many can be difficult to install. Installation typically requires both hands and a significant amount of force. Installation also often requires the aid of a common tool, such as a screwdriver, or the aid of a specialist tool, because the clip is deformed significantly from its original shape either temporarily or permanently to secures the wire to the dropper, hence the requirement of significant force to install. These drawbacks represent a significant issue when long distances of fence must be installed or maintained and repetitive strain injury (RSI) is a common consequence. Furthermore, whilst difficult to install, the wires can often be dislodged from the dropper relatively easily in many of these designs.
Examples of fence droppers and clip arrangements requiring a specialist tool for installation are disclosed in the following patents: U.S. Pat. No. 4,917,154, U.S. Pat. No. 5,518,044, U.S. Pat. No. 5,649,572, U.S. Pat. No. 6,044,872, U.S. Pat. No. 6,499,514 and U.S. Pat. No. 7,520,491. U.S. Pat. No. 3,977,653 discloses a fence post and fence clip that require a pair of pliers or a nail for installation. These patents also disclose a range of clip shapes and fence dropper shapes and a further example is disclosed in U.S. Pat. No. 1,761,452.
Nonetheless, in one particularly successful version, a plastic fence dropper comprises a hollow, box-shaped cross section and a plurality of shallow slots for holding fence wires. A complimentarily shaped symmetrical metal clip has a hook at each end. The clip fits around three sides of the box-shaped cross section and the hooks capture a wire either side of the fence dropper to secure the wire in a pair of slots in the fence dropper. A separate clip is used to secure each wire to the fence dropper. This particular design is cheap to produce and easy to ship and consequently enjoys a good market share. However, the fence dropper is made from low tensile poly ethylene (PE) and therefore is low in strength. This leads to a shorter life and therefore increased frequency of replacement. The low strength is evidenced by other fence droppers offered by the same manufacturer, which utilise an insert in the form of a galvanised metal post within the hollow plastic fence dropper. In addition to the additional cost and assembly of such fence droppers, the metal insert is not resilient and if the fence dropper is deflected beyond the elastic limit of the insert, the fence dropper will acquire a permanently deflected shape. The box-shaped cross section is also quite large, which results in a high delivery cost per unit and a high material consumption. The difficulty of installation mentioned above is also not adequately addressed.
There is a need to address or at least ameliorate one or more of the aforementioned problems of the prior art or to provide a commercially useful alternative.